. IY. IN" ANIMALS. 103
•t-*eydig,20 in a transitional condition; the fibres exhibit-
only indications of transverse striation.
Another explanation seems possible. We may admit
originally the arrectores pili were slightly acted on
a direct manner, under the influence of rage and
r, by the disturbance of the nervous system; as is
the case with our so-called goose-skin be-
fore a fever-fit. Animals have been repeatedly excited
rage and terror during many generations; and con-
tly the direct effects of the disturbed nervous
on the dermal appendages will almost certainly
been increased through habit and through the tend-
ency of nerve-force to pass readily along accustomed
oTaannels. We shall find this view of the force of habit
strikingly confirmed in a future chapter, where it will
t>e shown that the hair of the insane is affected in an
extraordinary manner, owing to their repeated accesses
of fury and terror. As soon as with animals the power
of erection had thus been strengthened or increased,
they must often have seen the hairs or feathers erected
ixx rival and enraged males, and the bulk of their bodies
tlans increased. In this case it appears possible that they
might have wished to make themselves appear larger and \
~nn.ore terrible to their enemies, by voluntarily assuming *'
a, threatening attitude and uttering harsh cries; such f.
attitudes and utterances after a time becoming through
ha/bit instinctive. In this manner actions performed ^
Toy the contraction of voluntary muscles might have been v
combined for the same special purpose with those ef- |
footed by involuntary muscles. It is even possible that i
animals/ when excited and dimly conscious of some ^
change in the state of their hair, might act on it by re- ''{;
;peated exertions of their attention and will; for we have \:
30 ' LelxrbTich. der Histologie,' 1857, s. 82. $